I think I may have come across a strange corner case. Either that or something were someone is going to have to explain to me some esoteric section of the specs.
The following query returns no results
select * where { } values ?test {"one" "two"}
while this one where I replace the wild card with a specific projection does
select ?test where { } values ?test {"one" "two"}
returns
+-------+
| test |
+-------+
| "one" |
| "two" |
+-------+
Yes, completely contrived query that you'd never do but it was surprising. I was going to use it to play around with UNNEST and SET to test some things to see if it worked the way I thought that it did.
If you move the values inside it works as expected. I guess the projection is applied before the values
select * where { values ?test {"one" "two"}}
+-------+
| test |
+-------+
| "one" |
| "two" |
+-------+